// wiringPanel.js — Wiring panel for connecting gadget ports to module ports
// The player wires a gadget's I/O to a module door's ports, then executes
// to verify the circuit satisfies the module's logic.

import { worldState, solvePuzzle, isPuzzleSolved, startDialog } from './worldState.js';
import { showNotification } from './inventory.js';

// ==================== State ====================

let panelOpen = false;
let moduleInter = null;   // the full interaction object from the map
let gadget = null;         // the selected gadget from backpack
let wires = [];            // [{ moduleIdx, gadgetIdx }]
let cursor = { side: 'module', index: 0 };
let selectedModule = null; // index or null (first port of a pending wire)
let selectedGadget = null;
let result = null;         // { message, color } or null
let resultTimer = 0;

// ==================== Public API ====================

export function isWiringOpen() { return panelOpen; }

/**
 * Open the wiring panel for a module interaction with a chosen gadget.
 * @param {Object} inter - The module interaction from the map
 * @param {Object} gad - The gadget from inventory
 */
export function openWiringPanel(inter, gad) {
    panelOpen = true;
    moduleInter = inter;
    gadget = gad;
    wires = [];
    cursor = { side: 'module', index: 0 };
    selectedModule = null;
    selectedGadget = null;
    result = null;
    worldState.mode = 'wiring';
    console.log(`[wiring] opened for module "${inter.label}" with gadget "${gad.name}"`);
}

export function closeWiringPanel() {
    panelOpen = false;
    moduleInter = null;
    gadget = null;
    wires = [];
    worldState.mode = 'world';
}

// ==================== Gadget port helpers ====================

/** Build a flat list of gadget ports (inputs first, then outputs) */
function getGadgetPorts() {
    if (!gadget) return [];
    const ports = [];
    const inputIds = gadget.inputIds || [];
    const outputIds = gadget.outputIds || [];
    for (let i = 0; i < inputIds.length; i++) {
        ports.push({ name: `In ${i + 1}`, dir: 'in', gateId: inputIds[i] });
    }
    for (let i = 0; i < outputIds.length; i++) {
        ports.push({ name: `Out ${i + 1}`, dir: 'out', gateId: outputIds[i] });
    }
    return ports;
}

// ==================== Input handling ====================

export function handleWiringInput(key) {
    if (!panelOpen) return false;

    const mPorts = moduleInter.ports || [];
    const gPorts = getGadgetPorts();

    switch (key) {
        case 'ArrowUp':
        case 'w':
        case 'W':
            cursor.index = Math.max(0, cursor.index - 1);
            break;
        case 'ArrowDown':
        case 's':
        case 'S': {
            const max = cursor.side === 'module' ? mPorts.length - 1 : gPorts.length - 1;
            cursor.index = Math.min(Math.max(max, 0), cursor.index + 1);
            break;
        }
        case 'ArrowLeft':
        case 'ArrowRight':
        case 'a':
        case 'A':
        case 'd':
        case 'D':
            cursor.side = cursor.side === 'module' ? 'gadget' : 'module';
            {
                const max = cursor.side === 'module' ? mPorts.length - 1 : gPorts.length - 1;
                cursor.index = Math.min(cursor.index, Math.max(max, 0));
            }
            break;
        case 'e':
        case 'E':
        case ' ':
            selectPort();
            break;
        case 'Enter':
            executeWiring();
            break;
        case 'Backspace':
        case 'Delete':
        case 'x':
        case 'X':
            removeWireAtCursor();
            break;
        case 'Escape':
            closeWiringPanel();
            break;
        default:
            return false;
    }
    return true;
}

// ==================== Wire management ====================

function selectPort() {
    if (cursor.side === 'module') {
        selectedModule = cursor.index;
        if (selectedGadget !== null) tryCreateWire();
    } else {
        selectedGadget = cursor.index;
        if (selectedModule !== null) tryCreateWire();
    }
}

function tryCreateWire() {
    const mPorts = moduleInter.ports || [];
    const gPorts = getGadgetPorts();
    const mPort = mPorts[selectedModule];
    const gPort = gPorts[selectedGadget];

    if (!mPort || !gPort) {
        selectedModule = null;
        selectedGadget = null;
        return;
    }

    // Validation: module-out → gadget-in, OR gadget-out → module-in
    const valid =
        (mPort.dir === 'out' && gPort.dir === 'in') ||
        (mPort.dir === 'in' && gPort.dir === 'out');

    if (!valid) {
        result = { message: '✗ Invalid! Wire out→in only', color: '#ff4444' };
        resultTimer = Date.now();
        selectedModule = null;
        selectedGadget = null;
        return;
    }

    // Remove any existing wire on either port
    wires = wires.filter(w => w.moduleIdx !== selectedModule && w.gadgetIdx !== selectedGadget);

    wires.push({ moduleIdx: selectedModule, gadgetIdx: selectedGadget });
    result = { message: `✓ Wired ${mPort.name} ↔ ${gPort.name}`, color: '#00e599' };
    resultTimer = Date.now();

    selectedModule = null;
    selectedGadget = null;
}

function removeWireAtCursor() {
    const key = cursor.side === 'module' ? 'moduleIdx' : 'gadgetIdx';
    const before = wires.length;
    wires = wires.filter(w => w[key] !== cursor.index);
    if (wires.length < before) {
        result = { message: 'Wire removed', color: '#ffaa00' };
        resultTimer = Date.now();
    }
}

// ==================== Circuit evaluation ====================

/**
 * Mini circuit evaluator — runs a cloned gadget circuit with given input values.
 * Returns an object mapping OUTPUT gate IDs → computed values.
 */
function evaluateGadgetCircuit(gates, connections, inputValues) {
    // inputValues = { gateId: 0|1 }
    const evalGates = JSON.parse(JSON.stringify(gates));

    // Set input gate values
    for (const g of evalGates) {
        if (g.type === 'INPUT' && inputValues[g.id] !== undefined) {
            g.value = inputValues[g.id];
        }
    }

    // Fixed-point iteration (max 20 passes)
    for (let iter = 0; iter < 20; iter++) {
        let changed = false;
        for (const g of evalGates) {
            if (g.type === 'INPUT' || g.type === 'CLOCK') continue;

            // Gather inputs from connections
            const inCount = (g.type === 'NOT' || g.type === 'OUTPUT') ? 1 : 2;
            const ins = [];
            for (let p = 0; p < inCount; p++) {
                const conn = connections.find(c => c.to === g.id && c.toPort === p);
                if (conn) {
                    const src = evalGates.find(s => s.id === conn.from);
                    ins.push(src ? (src.value || 0) : 0);
                } else {
                    ins.push(0);
                }
            }

            let val = 0;
            switch (g.type) {
                case 'AND':    val = (ins[0] && ins[1]) ? 1 : 0; break;
                case 'OR':     val = (ins[0] || ins[1]) ? 1 : 0; break;
                case 'NOT':    val = ins[0] ? 0 : 1; break;
                case 'NAND':   val = (ins[0] && ins[1]) ? 0 : 1; break;
                case 'NOR':    val = (ins[0] || ins[1]) ? 0 : 1; break;
                case 'XOR':    val = (ins[0] !== ins[1]) ? 1 : 0; break;
                case 'OUTPUT': val = ins[0] || 0; break;
                default:       val = g.value || 0;
            }

            if (val !== g.value) { g.value = val; changed = true; }
        }
        if (!changed) break;
    }

    return evalGates;
}

/**
 * Execute the wiring — build a test() function from the wires,
 * then run the module's verify function to check if the gadget passes.
 */
function executeWiring() {
    const mPorts = moduleInter.ports || [];
    const gPorts = getGadgetPorts();

    // Build the test function that the verify code will call.
    // test(moduleOutputValues) → moduleInputValues
    function test(moduleOutputs) {
        // moduleOutputs = { A: 0, B: 1, ... } — values for module's "out" ports

        // Map module output values → gadget input gates via wires
        const inputValues = {};
        for (const wire of wires) {
            const mp = mPorts[wire.moduleIdx];
            const gp = gPorts[wire.gadgetIdx];
            if (mp.dir === 'out' && gp.dir === 'in') {
                // Module provides value → gadget receives it
                inputValues[gp.gateId] = moduleOutputs[mp.name] || 0;
            }
        }

        // Evaluate the gadget circuit
        const evaluated = evaluateGadgetCircuit(gadget.gates, gadget.connections, inputValues);

        // Read gadget output gates → map back to module input ports via wires
        const moduleInputs = {};
        for (const wire of wires) {
            const mp = mPorts[wire.moduleIdx];
            const gp = gPorts[wire.gadgetIdx];
            if (mp.dir === 'in' && gp.dir === 'out') {
                const outGate = evaluated.find(g => g.id === gp.gateId);
                moduleInputs[mp.name] = outGate ? (outGate.value || 0) : 0;
            }
        }

        return moduleInputs;
    }

    // Run the verify function
    try {
        const verifyFn = new Function('return ' + moduleInter.verify)();
        const passed = verifyFn(test);

        if (passed) {
            result = { message: '⚡ VERIFIED! Module unlocked!', color: '#00ff88' };
            resultTimer = Date.now();

            // Mark as solved if it has an ID
            if (moduleInter.moduleId) {
                solvePuzzle(moduleInter.moduleId);
            }

            // Close after a brief delay and show dialog
            setTimeout(() => {
                closeWiringPanel();
                showNotification('Module unlocked!', '⚡', '#00ff88');
                startDialog([
                    `⚡ "${gadget.name}" passed the verification!`,
                    'The module hums to life and the door unlocks.'
                ], 'System');
            }, 800);
        } else {
            result = { message: '✗ Verification failed — wrong logic', color: '#ff4444' };
            resultTimer = Date.now();
        }
    } catch (e) {
        result = { message: `Error: ${e.message}`, color: '#ff4444' };
        resultTimer = Date.now();
        console.error('[wiring] verify error:', e);
    }
}

// ==================== Rendering ====================

const PANEL_BG = 'rgba(10, 12, 20, 0.95)';
const PANEL_BORDER = '#00e599';
const PORT_OUT_COLOR = '#ff6644';
const PORT_IN_COLOR = '#44aaff';
const WIRE_COLOR = '#ffdd44';
const SELECTED_COLOR = '#ffffff';
const CURSOR_COLOR = '#00ffcc';

export function drawWiringPanel(ctx, canvasW, canvasH) {
    if (!panelOpen || !moduleInter || !gadget) return;

    const mPorts = moduleInter.ports || [];
    const gPorts = getGadgetPorts();

    // Panel dimensions
    const pw = Math.min(640, canvasW - 40);
    const ph = Math.min(480, canvasH - 40);
    const px = (canvasW - pw) / 2;
    const py = (canvasH - ph) / 2;

    // Dim background
    ctx.fillStyle = 'rgba(0, 0, 0, 0.7)';
    ctx.fillRect(0, 0, canvasW, canvasH);

    // Panel background
    ctx.fillStyle = PANEL_BG;
    ctx.strokeStyle = PANEL_BORDER;
    ctx.lineWidth = 2;
    roundRect(ctx, px, py, pw, ph, 8);
    ctx.fill();
    ctx.stroke();

    // Title
    ctx.fillStyle = '#00e599';
    ctx.font = 'bold 16px "Segoe UI", system-ui, sans-serif';
    ctx.textAlign = 'center';
    ctx.textBaseline = 'top';
    ctx.fillText(`⚡ WIRING PANEL — ${moduleInter.label || 'Module'}`, px + pw / 2, py + 12);

    // Gadget name
    ctx.fillStyle = '#ff44aa';
    ctx.font = '12px "Segoe UI", system-ui, sans-serif';
    ctx.fillText(`Gadget: ${gadget.icon || '🔧'} ${gadget.name}`, px + pw / 2, py + 34);

    // Column headers
    const colY = py + 60;
    const leftX = px + 30;
    const rightX = px + pw - 30;
    const portStartY = colY + 30;
    const portSpacing = 40;

    ctx.font = 'bold 13px "Segoe UI", system-ui, sans-serif';
    ctx.textAlign = 'center';

    // Module ports header
    ctx.fillStyle = '#aaa';
    ctx.fillText('MODULE PORTS', leftX + 80, colY);

    // Gadget ports header
    ctx.fillText('GADGET PORTS', rightX - 80, colY);

    // Draw column separator
    ctx.strokeStyle = '#333';
    ctx.lineWidth = 1;
    ctx.beginPath();
    ctx.moveTo(px + pw / 2, colY + 15);
    ctx.lineTo(px + pw / 2, py + ph - 50);
    ctx.stroke();

    // Port positions for wire drawing
    const modulePortPositions = [];
    const gadgetPortPositions = [];

    // Draw module ports
    ctx.font = '13px "Segoe UI", system-ui, sans-serif';
    ctx.textAlign = 'left';
    for (let i = 0; i < mPorts.length; i++) {
        const port = mPorts[i];
        const yPos = portStartY + i * portSpacing;
        const isOut = port.dir === 'out';
        const dotX = leftX;
        const dotRadius = 8;

        // Port dot position (for wires)
        const wireX = leftX + 170;
        modulePortPositions.push({ x: wireX, y: yPos + 6 });

        // Highlight if cursor is here
        const isCursor = cursor.side === 'module' && cursor.index === i;
        const isSelected = selectedModule === i;

        // Background highlight
        if (isCursor) {
            ctx.fillStyle = 'rgba(0, 255, 200, 0.1)';
            ctx.fillRect(leftX - 10, yPos - 6, 190, portSpacing - 8);
        }

        // Port dot
        ctx.beginPath();
        ctx.arc(dotX, yPos + 6, dotRadius, 0, Math.PI * 2);
        ctx.fillStyle = isSelected ? SELECTED_COLOR : (isOut ? PORT_OUT_COLOR : PORT_IN_COLOR);
        ctx.fill();
        if (isCursor) {
            ctx.strokeStyle = CURSOR_COLOR;
            ctx.lineWidth = 2;
            ctx.stroke();
        }

        // Direction arrow inside dot
        ctx.fillStyle = '#000';
        ctx.font = 'bold 10px monospace';
        ctx.textAlign = 'center';
        ctx.textBaseline = 'middle';
        ctx.fillText(isOut ? '→' : '←', dotX, yPos + 6);

        // Port label
        ctx.textAlign = 'left';
        ctx.textBaseline = 'top';
        ctx.font = '13px "Segoe UI", system-ui, sans-serif';
        ctx.fillStyle = isCursor ? CURSOR_COLOR : '#ddd';
        ctx.fillText(`${port.name}`, dotX + 14, yPos);

        // Direction tag
        ctx.font = '10px monospace';
        ctx.fillStyle = isOut ? PORT_OUT_COLOR : PORT_IN_COLOR;
        ctx.fillText(isOut ? 'OUT' : 'IN', dotX + 14, yPos + 16);

        // Wire connected indicator
        const wire = wires.find(w => w.moduleIdx === i);
        if (wire) {
            ctx.fillStyle = WIRE_COLOR;
            ctx.fillText('⚡', dotX + 50, yPos + 16);
        }
    }

    // Draw gadget ports
    ctx.textAlign = 'right';
    for (let i = 0; i < gPorts.length; i++) {
        const port = gPorts[i];
        const yPos = portStartY + i * portSpacing;
        const isOut = port.dir === 'out';
        const dotX = rightX;
        const dotRadius = 8;

        const wireX = rightX - 170;
        gadgetPortPositions.push({ x: wireX, y: yPos + 6 });

        const isCursor = cursor.side === 'gadget' && cursor.index === i;
        const isSelected = selectedGadget === i;

        // Background highlight
        if (isCursor) {
            ctx.fillStyle = 'rgba(0, 255, 200, 0.1)';
            ctx.fillRect(rightX - 180, yPos - 6, 190, portSpacing - 8);
        }

        // Port dot
        ctx.beginPath();
        ctx.arc(dotX, yPos + 6, dotRadius, 0, Math.PI * 2);
        ctx.fillStyle = isSelected ? SELECTED_COLOR : (isOut ? PORT_OUT_COLOR : PORT_IN_COLOR);
        ctx.fill();
        if (isCursor) {
            ctx.strokeStyle = CURSOR_COLOR;
            ctx.lineWidth = 2;
            ctx.stroke();
        }

        // Direction arrow
        ctx.fillStyle = '#000';
        ctx.font = 'bold 10px monospace';
        ctx.textAlign = 'center';
        ctx.textBaseline = 'middle';
        ctx.fillText(isOut ? '→' : '←', dotX, yPos + 6);

        // Port label
        ctx.textAlign = 'right';
        ctx.textBaseline = 'top';
        ctx.font = '13px "Segoe UI", system-ui, sans-serif';
        ctx.fillStyle = isCursor ? CURSOR_COLOR : '#ddd';
        ctx.fillText(`${port.name}`, dotX - 14, yPos);

        // Direction tag
        ctx.font = '10px monospace';
        ctx.fillStyle = isOut ? PORT_OUT_COLOR : PORT_IN_COLOR;
        ctx.fillText(isOut ? 'OUT' : 'IN', dotX - 14, yPos + 16);

        // Wire connected indicator
        const wire = wires.find(w => w.gadgetIdx === i);
        if (wire) {
            ctx.fillStyle = WIRE_COLOR;
            ctx.fillText('⚡', dotX - 60, yPos + 16);
        }
    }

    // Draw wires
    ctx.strokeStyle = WIRE_COLOR;
    ctx.lineWidth = 2;
    ctx.setLineDash([6, 4]);
    for (const wire of wires) {
        const mp = modulePortPositions[wire.moduleIdx];
        const gp = gadgetPortPositions[wire.gadgetIdx];
        if (mp && gp) {
            ctx.beginPath();
            ctx.moveTo(mp.x, mp.y);
            // Bezier curve for nice look
            const midX = (mp.x + gp.x) / 2;
            ctx.bezierCurveTo(midX, mp.y, midX, gp.y, gp.x, gp.y);
            ctx.stroke();
        }
    }
    ctx.setLineDash([]);

    // Pending wire (half-selected)
    if (selectedModule !== null && selectedGadget === null) {
        const mp = modulePortPositions[selectedModule];
        if (mp) {
            ctx.beginPath();
            ctx.arc(mp.x, mp.y, 5, 0, Math.PI * 2);
            ctx.fillStyle = SELECTED_COLOR;
            ctx.fill();
        }
    }
    if (selectedGadget !== null && selectedModule === null) {
        const gp = gadgetPortPositions[selectedGadget];
        if (gp) {
            ctx.beginPath();
            ctx.arc(gp.x, gp.y, 5, 0, Math.PI * 2);
            ctx.fillStyle = SELECTED_COLOR;
            ctx.fill();
        }
    }

    // Result message
    if (result && (Date.now() - resultTimer < 3000)) {
        ctx.fillStyle = result.color;
        ctx.font = 'bold 14px "Segoe UI", system-ui, sans-serif';
        ctx.textAlign = 'center';
        ctx.textBaseline = 'bottom';
        ctx.fillText(result.message, px + pw / 2, py + ph - 35);
    }

    // Controls hint
    ctx.fillStyle = '#555';
    ctx.font = '11px "Segoe UI", system-ui, sans-serif';
    ctx.textAlign = 'center';
    ctx.textBaseline = 'bottom';
    ctx.fillText('↑↓←→: Navigate | E: Select/Wire | X: Remove | Enter: Execute | ESC: Close', px + pw / 2, py + ph - 10);
}

// ==================== Helpers ====================

function roundRect(ctx, x, y, w, h, r) {
    ctx.beginPath();
    ctx.moveTo(x + r, y);
    ctx.lineTo(x + w - r, y);
    ctx.quadraticCurveTo(x + w, y, x + w, y + r);
    ctx.lineTo(x + w, y + h - r);
    ctx.quadraticCurveTo(x + w, y + h, x + w - r, y + h);
    ctx.lineTo(x + r, y + h);
    ctx.quadraticCurveTo(x, y + h, x, y + h - r);
    ctx.lineTo(x, y + r);
    ctx.quadraticCurveTo(x, y, x + r, y);
    ctx.closePath();
}